JPS60327A - Vortex flow meter - Google Patents

Abstract

PURPOSE:To measure the number of Karman's vortexes accurately by communicating guiding inlets of fluid on both the side walls of a fluid path to be measured which is crossed with a vortex generator, connecting both the inlets through a straight pipe-like communication pile and fitting detectors to both the ends of the connection pipe. CONSTITUTION:The fluid guiding inlets 5, 6 are opened on the fluid path to be measured and communicated through the straight pipe-like communication path 7. The area of the flowing course of the straight pipe-like communication path 7 is set up smaller than the area of the flowing course of said fluid guiding inlets 5, 6 and the detectors consisting of ultrasonic transmitter and receiver 3, 4 e.g. are fitted to both the ends of the straight pipe-like communication path 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vortex flow meter that utilizes a Karman vortex generated by a vortex generator disposed in a fluid.

Figure 1 is a schematic configuration diagram for explaining an example of a conventional vortex flowmeter. In the figure, 1 is a fluid flow path to be measured through which a fluid to be measured flows, 2 is a vortex generator, and 3 is a vortex generator. An ultrasonic transmitter is disposed on a side wall of the fluid flow path to be measured 1 and intersects with the vortex generator 2, and 4 is an ultrasonic receiver disposed opposite to the ultrasonic transmitter 3. As is well known, when a columnar vortex generator 2 is inserted into a fluid flow path 1, the flow separates on both sides of the vortex generator 2, and regular vortexes are created alternately on the downstream side of the vortex generator. In other words, a Karman vortex is generated and fluid displacement occurs in the direction of the arrow.

Since the number of Karman vortices generated is proportional to the flow velocity or flow rate of the fluid, the flow rate can be measured by counting the number of Karman vortices. Conventionally, in order to count this Karman vortex, an ultrasonic transceiver is disposed across the Karman vortex, and the frequency modulation or phase modulation of the ultrasonic wave from the ultrasonic transmitter 3 is received by the ultrasonic wave. Vessel 4
However, external noises such as scattering of ultrasound waves by Karman vortices and reflections of ultrasound waves on pipe walls cause disturbances in the flow of the fluid to be measured, which can cause measurement errors. Ta.

” - 11 Kui The present invention was made in view of the above-mentioned circumstances.
The present invention relates to a vortex flow meter that can accurately measure Karman vortices without being affected by external noise.

Figure 2 is a cross-sectional configuration diagram for explaining one embodiment of the present invention. In the figure, parts having the same functions as those in Figure 1 are designated by the same reference numerals as in Figure 1. is attached. As is clear from FIG. 2, the invention does not provide an ultrasonic transmitter/receiver directly on the side wall of the fluid flow path 1 to be measured. Inlet ports 5 and 6 are provided, and both of these fluid inlet ports 5 and 6 are communicated through a straight tubular communication path 7, and the flow area of the straight tubular communication path 7 is set to be the flow path area of the fluid inlet ports 5 and 6. It is possible to make it smaller than the size of the straight pipe communicating path 7, and to arrange a detector consisting of, for example, ultrasonic transceivers 3 and 4 at both ends of the straight tubular communication path 7. Note that if an ultrasonic detector with a cone is used as the ultrasonic transmitter/receiver, the Karman vortex can be measured with higher accuracy.

Effects As is clear from the above explanation, according to the present invention, the pressure extracted from the pressure outlet is effectively converted into flow velocity, and the fluid in the straight tubular communication passage is not disturbed by external noise etc. Since the flow moves in the direction of the arrow in a substantially laminar flow, and the speed of movement is high, the number of Karman vortices can be measured with higher accuracy.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram for explaining an example of a conventional vortex flowmeter, and FIG. 2 is a cross-sectional configuration diagram of a vortex flowmeter according to the present invention. 1... Fluid flow path to be measured, 2... Vortex generator, 3...
Ultrasonic transmitter, 4... Ultrasonic receiver, 5, 6... Fluid inlet. 7... Straight tubular communication path. Figure 1 Figure 2.

Claims (5)

[Claims] (1) A vortex generator disposed in a fluid path to be measured, a fluid inlet opened on both side walls of the fluid path to be measured that intersects the vortex generator, and a fluid inlet connected to the inlet. A vortex flow meter characterized by having a straight communication pipe that communicates with the straight pipe and a detector that detects fluid displacement within the straight pipe. (2) A patent claim characterized in that the straight tubular communication passage has a central straight section cross-sectional area smaller than the cross-sectional area of the communication passage near both ends of the straight tubular communication passage and reaching the inlet. The vortex flowmeter according to item (1). (3) The vortex flowmeter according to claim (1) or (2), wherein a portion of the detector is in contact with the fluid to be measured. (4) The vortex flowmeter according to any one of claims (1) to (3), wherein the detector is attached to both ends of the straight tubular communication path. . (5) Claims (1) to (4) characterized in that the detector is an ultrasonic detection element with a cone.
The vortex flowmeter according to any one of the above items.